[Preliminary study on effect of surgical delay on anti-infection ability of reverse fascio-cutaneous flap]

To improve the success rate of the reverse fascio-cutaneous flap in repairing the infected wound, to observe the effect of surgical delay on the anti-infection ability of the reverse fascio-cutaneous flap by establishing an oryctolagus cuniculus model of reverse fascio-cutaneous flap based on sural nerve on the lateral side of left later limb.

Sixteen 5-month-old Japanese white rabbits weighing 2.0-2.5 kg (mean, 2.3 kg) were randomly divided into experimental group (n = 8) and control group (n = 8). The reverse fascio-cutaneous flap of 4 cm x 2 cm was designed, based on 1 cm above the lateral malleolar as pedicle in sural nerve region in the lateral left later limb. In the experimental group, the full-thickness of the flap distal end half was harvested according to the design; and after 10 days delay, the full-thickness flap was obtained according to the design, and 0.5 mL Staphylococcus aureus solution was implanted at a density of 3.8 x 10(6)/mL in 2 groups. The general observation was performed postoperatively; the venous blood of the marginal ear vein was collected to observe white blood cell (WBC) count before implantation of staphylococcus aureus solution and after 1, 3, 5, 7, 10, and 14 days of implantation. The flap survival rate and the colony counting of necrosis flap tissue were calculated after 10 days of implantation; the blood vessel caliber and the peak value of peroneal artery blood flow of flap proximal end were measured after 14 days of implantation.

All animals survived to the end of the experiment, and all incisions healed primarily. Inflammatory reaction with different degrees was observed after implantation in 2 groups, and it was obvious at 3-5 days. Inflammatory reaction in the experimental group was slighter than that in the control group. Except for no significant difference before implantation and after 14 days of implantation between 2 groups (P > 0.05), there were significant differences in WBC count at other time points between 2 groups (P < 0.05). The flap survival rate of the experimental group (93.20% +/- 4.62%) was significant higher than that of the control group (72.65% +/- 7.80%) after 10 days of implantation (P < 0.05). The colony counting of necrosis flap tissue in the experimental group [(20.63 +/- 5.76) x 10(3) colony/g] was significantly lower than that in the control group [(32.38 +/- 6.14) x 10(3) colony/g] after 10 days of implantation (P < 0.05). The blood vessel caliber of the experimental group and the control group were (1.03 +/- 0.10) mm and (0.75 +/- 0.09) mm, respectively, and the peak value of peroneal artery blood flow in the experimental group and the control group were (20.73 +/- 2.46) cm/s and (13.83 +/- 1.51) cm/s, respectively, after 14 days of implantation; showing significant differences between 2 groups (P < 0.05).

Surgical delay has the ability of enhancing survival and anti-infection of the rabbit reverse fascio-cutaneous flap.